The present invention relates to cardiovascular catheters. In particular, the present invention relates to a catheter for temporary placement in the coronary sinus and right atrium for atrial cardioversion.
Electrophysiology (EP) catheters are well recognized and important tools for performing a variety of functions such as recording the heart""s electrical signals, pacing the heart, or cardioverting the heart. For recording electrical activity in the heart, EP catheters are used to record intracardiac electrograms. When positioned in the heart, an EP catheter records the electrical activity between a pair of electrodes at the distal end of the catheter to provide a recordation of the electrical activity of a localized area of the heart near the electrode pair. By using multiple EP catheters positioned in the heart, one can map the sequence of myocardial depolarization as an electrical impulse traverses the heart.
EP catheters may also be used for pacing and/or cardioversion. For pacing, a pulse of electrical current is carried by the catheter from an external pacemaker to the heart where it causes cardiac cells near the catheter""s electrodes to depolarize. The depolarization of these cardiac cells is then propagated across the heart as if the impulse arose from the heart itself. For cardioversion, a high energy electrical charge is applied to the heart using an EP catheter causing instant and rapid depolarization of all cardiac cells in an attempt to restore the heart to normal sinus rhythm.
Current EP catheters include distal portions having a variety of ring electrodes, tip electrodes, coil electrodes, and large surface electrodes. Moreover, some systems include multiple EP catheters. Despite the variety of catheter components and combinations of these components on one or more EP catheters, no prior art catheter(s) has yet achieved an optimal arrangement of electrically-active components for a coronary sinus catheter for atrial cardioversion.
The present invention provides a coronary sinus catheter including a distal electrode portion with optimally-spaced and sized ring electrodes and a proximal electrode portion with at least one optimally-spaced and sized larger surface electrode. This catheter reduces energy thresholds for efficacious atrial defibrillation and allows for strategically-placed, multiple defibrillation vectors with a single catheter. The catheter further includes at least two distal curve portions to facilitate placement of the distal electrode portion within the coronary sinus and the proximal electrode portion within the right atrium and/or other vessels.
The catheter has all or some of the following features. First, at least one ring electrode of the distal electrode portion includes a first diameter less than a second diameter of at least one, more proximally disposed, ring electrode of the distal electrode portion. Second, at least one ring electrode of the distal electrode portion includes a first width less than a second width of at least one, more proximally disposed, ring electrode of the distal electrode portion. Third, the distal electrode portion includes a first, hook-type distal curve and a second, smoother proximal curve. Fourth, the distal electrode portion includes at least two ring electrodes and the proximal electrode portion includes at least two larger surface coil electrodes. Fifth, the catheter further includes a collapsible section, adjacent the proximal electrode portion, to facilitate positioning of the catheter within the right atrium.
With these features, a coronary sinus catheter of the present invention is uniquely adapted to deliver electrical signals for monitoring and defibrillation of the right atrium and coronary sinus region.